With C57 mice and the ob/ob and db/db variants, the role of formation of mixed disulfides in the control of metabolism in the fed and fasted state will be determined. Similar studies will be made with mice made diabetic with streptozotocin or by infection. The CD1 mouse, a model of adult onset diabetes, will be studied in the same manner. Dietary and other systems of control will be investigated. In vitro studies are to be on a small protein that readily forms mixed disulfides and on a relatively unrecognized control enzyme, inorganic pyrophosphatase.